More expensive X-Pro adapters?
As a matter of curiosity, among third-party adapters being sold on Ebay and in other places, why would one (essentially) no-name brand command a premium over another? Leica M adapters range from $180 for Rayqual to about $80 for a Kipon, all the way down to $25 for a no-name Chinese M adapter.
Does anything substantiate any quality difference between any of these? Obviously, some have chrome (or bare aluminum) lens mounts and some do not, but there is no apparent correlation to how much they cost.
The only possible difference I can imagine is that some might focus precisely at infinity and some might not, but just about every adapter I have seen focuses beyond infinity to some degree in an attempt to avoid machining the depth of the adapter to a high standard.
Is this a case of Chinese sellers just trying to feel out prices? Or is there something else to this?